The invention relates to a rotary printing press.
Rotary printing presses have several printing units based on printing plates to print at least one substrate web, in particular multiple substrate webs, preferably printing them on both sides. The printing units based on printing plates are offset printing units in particular, whereby, with the help of offset printing units, the/each substrate web may be printed conventionally with a static print image, which is thus identical for all print copies of a print job. In the case of rotary printing presses, there is growing demand for printing the substrate webs, not only conventionally and statically by offset printing, but also individualizing the substrate webs in terms of printing technology by also printing the substrate webs dynamically by using printing units that do not use printing plates and/or are preferably designed as inkjet printing units, in addition to using static offset printing. It is already known from practice that plate-free printing units may be integrated into the rotary printing press downstream from the printing units that use printing plates and upstream from a folder, so that dynamic printing may be performed inline with static printing.
To ensure proper operation of plate-free printing units, such as inkjet printing units, it is necessary to regularly maintain the plate-free printing units and adjust their printing parameters, so that high-quality dynamic printing may be performed using the plate-free printing units, depending on the printing speed of the printing plate-based printing units that are used for static printing.
Thus, with a continuous inkjet printing unit, for example, a charging voltage of the electrodes and a phase ratio of a trigger voltage must be adapted for individual ink droplets, based on an input signal, to ensure a high print quality.
It is already known from practice that a plate-free printing unit may be designed to be portable and/or movable, so that they can be shifted from a printing position in which a substrate web is printable by the plate-free printing units, to a service position in which no substrate web is printable by the plate-free printing units, so that cleaning operations and adjustment operations may be performed on the plate-free printing units in the service position. In the past, problems have been encountered in verifying whether printing parameters set on a plate-free printing unit yield a good print quality.
With the printing presses known in practice, such verification may be performed only by printing the substrate web using a plate-free printing unit, and then individual print copies must be removed from the production stream to verify the print quality. This poses problems with rotary printing presses, because individual copies exist only in the area of the folder and can be removed for verification of whether printing parameters set on a plate-free printing unit result in a good print quality, so that, under some circumstances, a number of sheets of waste paper must be printed. There is, therefore, a demand for a rotary printing press on which the print quality achievable with the help of a plate-free printing unit can be verified easily while minimizing spoilage.
Against this background, the object of the present invention is to create a novel rotary printing press.
According to the invention, a device which is printable by at least one plate-free printing unit shifted into the service position, so that the printing parameters of the plate-free printing unit can be verified and adapted to subsequent printing of a substrate web in the printing position, is provided in the service position, according to this invention.
In the sense of the present invention, a device which is printable by at least one plate-free printing unit that has been shifted into the service position, is assigned to the service position for at least one plate-free printing unit, such that the print quality achievable by using the printing parameters set on the plate-free printing unit can be verified without printing the actual substrate web. In the service position, printing parameters of the plate-free printing unit can be adapted to subsequent printing of a substrate web, so that a plate-free printing unit can be set up for printing with virtually no spoilage.
Preferred further embodiments of the invention are derived from the following description. One exemplary embodiment of the invention, without being limited to this, is explained in greater detail below with reference to the drawings.